Suppose that the transaction T1 and T2 access the same database items.
$$\begin{array}{|l|l|} \hline T1 & T2 \\ \hline \text{read(X)} & {} \\ X=X-N & {} \\ \hline {} & \text{read(X)} \\ {} & X=X+N \\ \hline \text{write(X)} & {} \\ \hline {} & \text{write (X)} \\ \hline \end{array}$$
Which one of the following statements is correct about these two transactions?
- Dirty Read will occur
- Lost update will occur
- Both T1 and T2 are serial schedule
- This is an example of uncommitted data problem